EP3383620A1

EP3383620A1 - Device for welding tubes

Info

Publication number: EP3383620A1
Application number: EP16804752.0A
Authority: EP
Inventors: Peter BÜHLER; Willy Fluder; Markus Wyss
Original assignee: Reed Electronics AG
Current assignee: Reed Electronics AG
Priority date: 2015-11-30
Filing date: 2016-11-29
Publication date: 2018-10-10
Anticipated expiration: 2036-11-29
Also published as: CN108883582B; CA3006794A1; BR112018010951A2; CN114851577A; CN108883582A; AU2016363634B2; US11077623B2; HRP20211175T1; DK3383620T3; EP3912803A1; HUE055235T2; EP3912803B1; ES2877519T3; SI3383620T1; CH711822A1; PT3383620T; AU2016363634A1; BR112018010951B1; JP2019501807A; WO2017093216A1

Abstract

The invention relates to a device for welding thermoplastic tubes (1, 2), to a welding method, and to a welding knife. The device according to the invention is provided for welding thermoplastic tubes (1, 2), wherein the tubes (1, 2) are placed into tube holders (100, 200) and squeezed with the aid of tube clamps. A welding knife is moved between the first and the second tube holder and severs the tubes (1, 2) in the process. Cut ends and residual ends are thereby produced. The cut ends are aligned with one another by a relative movement of one tube holder (100) with respect to the other tube holder (200) and, by a horizontal movement of the two tube holders (100, 200), are welded simultaneously to form continuous tubes.

Description

Device for welding hoses

TECHNICAL AREA

The invention relates to a device for welding thermoplastic hoses, a method for welding and a welding knife.

STATE OF THE ART

From US461 0670 A an apparatus and a method for the sterile connection of two thermoplastic tubes is known. In this method, the ends of two tubes are connected to each other, each with one end open into a blood bag. For this purpose, the two hoses are inserted parallel to each other into two blocks spaced apart from one another, severed with a heated knife and joined to form a continuous hose. The aim is to create a sterile connection between two tubes.

EP0208004 A1 discloses a method and apparatus for sterile docking of plastic tubing sections. Similar to US 461 0670 A, two hose ends are joined to a continuous hose with the difference that two already cut hose ends are clamped in holding blocks, heated by a heater and joined together by a horizontal displacement of the holding blocks and welded together. US 201 2/0269679 A1 discloses a system with which a multiplicity of hoses, which are each connected at their one end to a blood bag with a plurality of hoses. In the disclosed method, individual heated blades are used to separate the tubes and to weld them together in a further step. SUMMARY OF THE INVENTION In the disclosed method, individual heated blades are used to seal the tubing

When processing blood products, highly automated processes are used. Therefore, high demands are placed on the machine used for this purpose in terms of efficiency and sterility. An essential step is the connection of several blood bags together, in which the individual tubes, which lead away from the individual bags, are welded together. In blood banks, more than 2,000 welds on hundreds of blood bags per day are made to connect the individual blood banks, for example to produce platelet concentrate from donated blood. It is therefore necessary to be able to carry out as many welds as quickly as possible and of high and consistent quality. It should be made a sterile connection. The object of the invention is to provide a device and a method for welding a plurality of thermoplastic tubes, which has the advantages mentioned above and avoids disadvantages of the prior art.

A further object is to provide an apparatus, a method and a heatable welding knife, wherein a plurality of thermoplastic tubes are cut and whose ends are to be welded with consistent quality. The tasks are solved by the claim characteristics. Preferred embodiments of the invention are indicated in the dependent claims.

The device according to the invention for welding thermoplastic hoses of a first and second hose group comprises two hose holders each having a first and a second hose clamp, and a welding knife. The hoses of the first hose group run straight through between the two hose holders, are inserted into the through holes of the first two hose clamps and squeezed therein.

The hoses of the second hose group also run straight through between the two hose holders, are inserted into through holes of the two second hose clamps and squeezed therein.

The welding knife is moved between the first and second tube holders and is configured to sever the crimped tubes of the first and second tube groups in a movement to thereby produce cut ends and residual ends.

One of the two tube holders can be displaced relative to the other tube holder, thereby aligning the cut ends of the tubes.

The two tube holders can also be moved in a horizontal direction to each other or away from each other to thereby simultaneously weld a respective cut end of a tube of the first tube group, each having a cut end of a tube of the second tube group to a continuous tube. An advantage of the device according to the invention is that in this way a multiplicity of thermoplastic tubes can be welded in a sterile manner to continuous tubes with a small number of working steps.

According to the invention, the passage openings of the two first hose clamps are arranged on a first plane and the passage openings of the two second hose clamps are arranged on a second plane, wherein the first plane is arranged parallel to and spaced from the second plane.

In a preferred embodiment of the invention, the two first hose clamps and the two second hose clamps have pinch zones, wherein these pinch zones run along the through openings and are adapted to squeeze the inserted hoses at an oblique angle to the first or second plane.

According to the invention, the welding knife can be clamped in a welding knife holder and a drive unit is set up to move the welding knife holder in a vertical direction in order to cut through the tubes. In this vertical movement, one of the two tube holders is vertically displaced relative to the other tube holder for aligning the cut ends of the tubes. Furthermore, according to the invention, the two tube holders are moved towards or away from each other in the horizontal direction by the movement of the welding knife holder in the vertical direction or both tube holders are moved simultaneously in one direction.

In a preferred embodiment, the device has a platform movable in the vertical direction and the welding knife holder is arranged on this platform. According to the invention, the welding knife holder has two clamping parts lying opposite one another, between which the welding knife can be clamped. Preferably, one of the two clamping parts is fixed and the other arranged relatively movable to the fixed clamping part. Further, a pair of first link supports is provided on one of the two clamping parts. In one embodiment, the clamping member and the pair of first link supports are made as one piece. Alternatively, the pair of first link supports is mounted on one of the two clamping parts as separate parts.

The pair of slide supports preferably has a total of four first scenes. These scenes are identical to each other and arranged mirror-symmetrically to a plane of the welding knife when the welding knife is clamped between the two clamping parts.

Furthermore, pairs of scanning wheels are provided which scan the scenes in the vertical direction during the movement of the welding knife holder and thereby move the hose holders in the horizontal direction to one another or away from one another or both hose holders simultaneously in one direction.

According to the invention, a second slide carrier and a further scanning wheel are provided. The further scanning wheel is set up to scan the second slide carrier in the vertical direction during the movement of the welding knife holder. In this case, the one clamping part is moved relative to the second fixed clamping part and in this way varies the distance between the two clamping parts.

When scanning the second link carrier by the Abtastrad the distance between the two clamping parts is preferably varied in three different positions. In a receiving position, the Abtastrad is in contact with the second slide carrier and there is a gap between the two clamping parts, which is just needed for the insertion of the welding blade.

In a contacting position, the distance between the two clamping parts is selected so that the welding knife is clamped and at the same time electrically contacted. In this position, the scan wheel is not in contact with the second slide carrier.

In a release position, the scan wheel is in contact with the second slide carrier, and the distance between the two clamping parts is selected so that the welding knife can be ejected. In a preferred embodiment, pressure pieces are arranged on at least one of the two clamping parts, which contact the welding knife in the contacting position. In one embodiment, these pressure pieces are resiliently mounted on the at least one clamping part. Due to the resilient mounting of the pressure which is exerted during the contacting of the welding knife, can be adjusted variably. It has been found that the most regular possible pressure distribution on the welding knife causes a regular temperature distribution over the surface of the welding knife. As uniform a distribution as possible is desirable because it improves the quality of the weld. It is then ensured that a comparable heat energy, regardless of their position in the hose holder, is applied to the cut ends or the remaining ends of the thermoplastic tubes.

According to the invention, the device has a transformer unit with a primary winding and a secondary winding, wherein the secondary winding is formed by a single conductor. This conductor is with one of the two clamping parts, preferably with the fixed clamping part, connected. The welding knife closes the secondary circuit in the contact position and forms therein the main resistance element in which the power loss predominantly occurs. The welding knife is heated to the desired temperature. The welding knife is heated with a high alternating current to a temperature of around 300 ° C. With the arrangement according to the invention, it was possible to achieve a constant heating power on the welding knife. Thanks to the construction according to the invention, the electrical system can be well integrated into the housing of the device. According to the invention, the first and the second hose group each have the same number of individual hoses, preferably more than two, in particular six hoses per hose group.

The inventive method for welding a plurality of tubes of a first and a second tube group with the inventive device comprises a plurality of steps.

At the beginning, the hoses of the first and the second hose group are inserted and squeezed in parallel and one above the other in directly opposite first and second hose holders. A heated welding knife is placed in a welding knife holder and heated to a desired temperature.

The heated weld knife is moved between the first and second tube holders, severing the crimped tubes in cut ends and remnant ends at the same time.

The cut ends of the hoses are melted by the heated welding knife. The cut ends of the tubes of the first tube group are aligned with the cut ends of the tubes of the second tube group, in which one of the two tube holders is displaced relative to the other tube holder, so that the cut ends of the tubes of the first tube group are symmetrically opposite to the other Cut ends of the second tube group are arranged and the welding knife can be pulled out.

The two tube holders are displaced toward one another in order to simultaneously weld one cut end of the tubes of the first tube group, each with one cut end of the tubes of the second tube group, to one continuous tube each.

Finally, the welding knife is ejected from the welding knife holder.

When inserting the welding knife (4), the horizontal distance between the first and the second hose holder (1 00, 200) d 1. When cutting through the crimped tubes, the distance on d4 is increased. When the cut ends melt, the distance is d2, where d Kd2 <d4. When moving one of the two hose holders (100, 200), the distance is increased again to d4. When welding, the distance is d3, where d3 <d4 and when ejecting the welding knife, the distance between the two hose holders (1 00, 200) is d5, where d5 represents the smallest of all five distances.

The distance d4 is selected in size so that a tensile stress is applied to the thermoplastic tubes. A severance is thereby facilitated. When melting the cut ends, the distance is reduced to d2. In this way, the cut ends and the remainder ends touch the heated welder and become attached Melted according to their cross sections. When moving one of the two hose holders, the distance is increased again to d4. Increasing the distance to d4 ensures that when the welding knife is pulled out, sufficient melting material remains on the tube cross-sections, which is then available for subsequent welding. Thereafter, a respective cut end of a tube of the first tube group, each with a cut end of a tube of the second tube group to a continuous tube welded simultaneously, in which the ends are joined by reducing the distance between the tube holders on d3. Finally, the welding knife is ejected and the welded hoses are removed. The hose holders are at a distance d5 to each other, which is usually so small that they touch each other.

The welding knife according to the invention, which is preferably used in the apparatus according to the invention or in the method according to the invention, has a multiplicity of recesses in its sectional area. According to the invention, the cut surface serves to melt the cut ends or the remainder ends of the hoses, so that in the following a melt surface is mentioned.

It has been found that the recesses and in particular their arrangement and / or number has an influence on the vertical and horizontal temperature distribution with respect to the welding knife surface. A regular distribution is advantageous, since in this way the most uniform possible melting of the cut ends of the thermoplastic hoses is ensured and a good welding result is ensured.

In a preferred embodiment, the melt surface has a rectangular shape and along the two short sides of the rectangle edge zones are provided, which are adapted to contact a secondary side of a transformer unit. Preferably, this contacting takes place via the pressure pieces, which are arranged on one of the two clamping parts.

The recesses in the melt surface are arranged along the edge zones of the melt surface.

The welding knife according to the invention has a blade on one of the two longer sides of the rectangle, the blade having a symmetrical shape relative to the cross section of the rectangle. This form is advantageous because the welding blade thereby produces a very straight cut when cutting the tubes. In one embodiment, the welding knife is made by half longitudinal folding of a double width sheet. As a blade which cuts the tubes, the bending edge along which the two halves of the leaflet are connected serves. This results in a symmetrical rounded blade.

As an alternative to folding, the welding knife is produced by stamping and its blade by embossing. The embossing is made along a longitudinal side of the leaflet, in which the desired blade shape is pressed along the longitudinal side. As a result of this design, a cutting edge which is not too sharp but rounded, but above all even and symmetrical on both sides, is provided in a rational manner. The inventive welding knives are stored in a box, which is preferably exchangeable as a whole. BRIEF EXPLANATION OF THE FIGURES

The invention will be explained in more detail with reference to an embodiment in conjunction with the drawings. Show it:

1 shows a perspective view of the inventive device in a view obliquely from above with table and legs,

1 A shows a perspective view from above of the device according to the invention with closed tube holders and inserted tubes,

2 shows a view of the inventive device from below,

3 shows a part of the device according to the invention in a perspective view with opened tube holders,

4 shows a sectional view of the device according to the invention, wherein the welding knife holder is in a position in which the welding knife can be received ("bladefeed position"),

4A shows the device according to the invention in the "bladepickup position" with some parts removed so that the view of the welding knife feed and one of the welding knife holders is clear,

4B shows the partial view from FIG. 4A at the time when the welding knife is inserted into the welding knife holder, FIG. 5 shows a sectional view of the device according to the invention in a position in which the welding knife is inserted into the welding knife holder and electrically contacted ("precut position"),

Fig. 6 shows a sectional view of the inventive device in one

Position in which the first and the second tube holder are spaced from each other in such a way that the inserted tubes are stretched ("stretch position"),

Fig. 7 shows a sectional view of the inventive device in one

Position in which the hoses are severed by the welding knife and the first and second hose holders are displaced in the vertical direction and the hoses are aligned ("cut position"),

Fig. 8 shows a further sectional view of the embodiment with inserted

Hoses, wherein the first and the second hose holder are displaced in the vertical direction against each other and the hose ends to be welded aligned and joined ("Press Position") and the welding knife is no longer between the hose holders,

Fig. 9 shows a sectional view of the inventive device in one

Position in which the welding knife is ejected ("eject position"),

10A shows a preferred embodiment of a welding knife, FIG. 11 shows the vertical and horizontal temperature distribution on the welder along first, second and third lines. FIG.

In the various figures, the same parts are given the same reference numerals. Of several identical parts, only one is always provided with a reference sign.

WAYS FOR CARRYING OUT THE INVENTION

Figure 1 shows a perspective view from above of the inventive device of the embodiment, which is constructed on or on a table 700. The table is on four legs 701. The device has two hose holders 100, 200, in which hoses are inserted, wherein the hoses of a first hose group 1 extend on a first level and the hoses of a second hose group 2 on a second level above. The two hose holder 1 00, 200 additionally have clamping lever 1 0, 20.

In FIG. 1A, a box 500, in which welding knives are stored, is visible through a cutout 702 of the table 700 produced for this purpose, and a welding knife feed 600 to a welding knife holder 40. The latter is arranged underneath the hose holders 100, 200 that it is not visible in both figures 1 and 1 A. Welding knife feeder 600 includes a slide 601 for a slider 60 and a driver 602, which may be a DC Planetary Gear Brush Motor, for example in such a way that the individual welding knives 4 arranged in the longitudinal direction are sorted into the box 500 (not visible in Figure 1) .The box 500 is on the side which leads to the welder feeder 600 oriented, open. A spring element arranged in the box (not visible in FIG. 1) pushes the welding knife 4, which is intended for the next welding operation, into the guide rails 61 of the welding knife feed 600.

Arranged under the table 700 is a platform 400 on which the welding knife holder 40 (not visible in FIG. 1) is mounted. The platform 400 and welding knife holder 40 can be moved to and from the table 700 by means of a further drive unit 401 (arrow Y), d. H. when the table is oriented horizontally, move up and down in the vertical direction.

In FIG. 1 as well as in the other figures, the illustration of a housing which is usually additionally present is dispensed with. From the housing, preferably, the hose holder 1 00, 200 protrude upward, so that the housing for inserting or removing the hoses must not be opened. In addition, the box 500 with the cutting knife stock should be easily accessible for replacement, made possible by means of a 704 drawer. Control elements such as a start button 705 may also be provided on the housing (see, for example, Figure 1, 1 A).

Figure 2 shows the device according to the invention in a view from below, wherein the platform 400, on which the welding knife holder 40 is placed, and more of the drive unit 401, which moves the platform 400 in a vertical direction. It comprises three gears 402 403 and 407, wherein the gear 402 is connected via a connecting rod 405 to the platform 400. The gear 407 is located between the gear 402 and 403 (visible in Figure 2). The connecting rod 405 converts the circular movement of the gear 402 into a linear up and down movement of the platform 400 along rod-shaped guides 406. The gear 403 is driven by a motor 404, which is for example again a "DC Planetary Gear 2 is also visible a transformer unit 90 for heating the welding blade 4, which will be described in more detail below.

FIG. 3 shows a part of the device according to the invention in a perspective view with opened tube holders 1 00, 200, without inserted tubes. The first and the second hose holder 1 00, 200 each include a first 1 01, 201 and a second hose clamp 1 02, 202. The first hose clamp 1 01 of the first hose holder

1 00 and the first hose clamp 201 of the second hose holder 200 each have a lower part and an upper part. The second hose clamp 1 02 of the first hose holder 1 00 and the second hose clamp 202 of the second hose holder 200 also each have a lower part and an upper part. The top of the first hose clamp

1 01 of the first tube holder 1 00 and the upper part of the first tube clamp 201 of the second tube holder 200 simultaneously form the lower part of the second tube clamp 1 02, 202 of the first and second tube holder 1 00, 200. Each tube clamp has through holes 1 1, 1 2, 21 and 22, in which the hoses of a first and a second hose group are inserted. The through holes 1 1, 21 of the two first hose clamps 1 01, 201 are arranged on a first level and the through holes 1 2, 22 on a second level. The first plane is parallel and vertically spaced from the second plane. The first two hose clamps 1 01, 201 and the two second hose clamps 1 02, 202 have first and second pinch zones 3 1, 32, which are set up to squeeze the inserted hoses before severing. The crush zones 3 1, 32 are sawtooth-shaped, so that the tubes are crushed at an oblique angle, in particular from 25 ° - 30 °. By squeezing the hoses are completely closed, so that in particular in the hoses contained liquid, for example, from blood preserves, the pinch zones can no longer happen. Visible further in FIG. 3 is the welding knife holder 40 with a first clamping part 43, which is arranged opposite to a second clamping part 44 and is movable relative to this second, fixed clamping part along rod-shaped guides 520. The two clamping parts each have a pair of angled clamping arms 431, 441, the welding blade 4 being held between the upwardly projecting portions of these clamping arms. For pressing the first clamping member 43 against the second clamping member 44 first springs 51 are used.

Attached to the clamping part 44 is a pair of slide supports 41, on whose uprising sections on both sides and thus a total of four first scenes 41 1 are formed. Alternatively, the clamping part 44 and the pair of slide supports 41 are formed as a part. The scenes 41 1 are identical to each other and arranged mirror-symmetrically to the plane of the welding blade 4, when this is clamped between the clamping parts 43, 44. Further, in the rear link support 41 in FIG. 3, there is a slot 42 for the insertion of the welding blade 4 between the two clamping parts 43, 44 (not visible in FIG. 3).

Also visible in FIG. 3 are further parts of a heater for the welding knife 4, which comprises the transformer unit 90 already mentioned. To a hollow cylindrical ferrite core of this unit is distributed over the circumference of a primary winding through a plurality of turns copper wire, for example 5- 1 5 turns, wound, with the individual windings extend substantially in the axial direction of the ferrite core and therethrough. In contrast, the secondary winding is formed only by a single conductor which extends straight through the ferrite core and is bolted endwise to the lower portions of the clamping arms 441 of the clamping member 44 (screw 901). The clamping arms 441 are electrically conductive and form parts of the secondary circuit, which is also provided by the likewise electrically conductive welding knife 4 is closed as soon as it is clamped between the first 43 and the second clamping member 44 and in contact with the clamping arms 441. Since the welding blade 4 has a substantially smaller cross-section and a higher resistivity relative to the straight conductor forming the secondary winding and the two clamping arms 441, its electrical resistance is comparatively high, so that the majority of the electrical power loss of the secondary circuit is produced in it. In addition, results from the transmission ratio of the transformer unit 90 with the only one turn in the secondary circuit, a high secondary current, so that the welding knife is heated very effectively and quickly within 3 to 4 seconds to the desired temperature of about 300 ° C. Currents greater than 1 00 A can be achieved here.

4 shows a sectional view of the device according to the invention, wherein the platform 400 and with it the welding knife holder 40, which is movable in the vertical direction of the arrow Y to the table 700, is in the so-called "bladefeed position." In this position is the Welding knife holder 40 at a height so that the welding knife 4 can be inserted through the slot 42 between the two clamping parts 43, 44. For this purpose, the two clamping parts 43, 44 are slightly spaced apart The effect of the springs 51 is set by scanning a second slide 451 on a second slide carrier 45 with the aid of a scanning wheel 52. In the "bladefeed position", the scanning wheel 52 is located on the second slide 451 in a receiving position (B) in which the two clamping parts 43, 44 just have the necessary for the insertion of the welding blade 40 distance from each other.

The two hose holder 1 00, 200 are each mounted slidably in the table 700 and thus not only against each other, but also in the same direction with each other. By second springs they are biased against each other. The corresponding second Springs are designated in Figure 4 with 203, 203 '. On the hose holders 1 00, 200 a pair of scanning wheels 53 is further stored in each case. The total of four scanning wheels 53 cooperate with the aforementioned four first scenes 41 1 on the link supports 41 when, as in the "bladefeed position" shown in FIG. 4, the scanning pairs 53 intervene Slots 41 1, the horizontal distance d 1 between the two tube holders 1 00, 200 is set. In the "Bladefeed position" shown in Figure 4, the first and the second tube holder 1 00, 200 at a distance d 1 to each other. By the four first scenes 41 1 are identical and mirror-symmetrical to the plane of the welding blade 4 are formed and the two hose holder 1 00, 200 are displaced in the same direction with each other, the hose holder 1 00, 200 are always aligned relative to the welding blade holder 40 so that the welding knife is located exactly in the middle between the two hose holders 1 00, 200. Any tolerances between the platform 400, which carries the welding knife holder 40, and the table 700, on which the hose holders 100, 200 are mounted, are thereby compensated.

FIG. 4A shows a part of the device according to the invention. Shown is one of the two tube holder 1 00 with the clamping lever 1 0, arranged on the table 700. The second half of the device comprising the second tube holder 200 and the second clamping member 44 is omitted in Figure 4A. Partially visible thereby is the welding knife holder 40 with the first clamping part 43. The welding knife holder 40 is in the "bladefeed position" as described in Fig. 4. The hoses of the first and second tube groups 1, 2 should be in this position however, they are also omitted in Figure 4. The welding knife feed 600 comprises the slide 60, which is moved by the slide 601 along guide rails 61 and driven by means of a further drive 602 (cf. 1 A). The slide 60 is used to introduce the welding knife 4 in the Welding knife holder 40 moves in the direction of the arrow X, taking with it the welding knife 4. A new welding knife is introduced per welding process so that each welding knife 4 is used only once. A larger number of welding knives 4 are stored in the box 500. The box 500 is configured in such a way that in each case one welding knife 4 is advanced into the region of the guide rails 61 per welding operation, so that it can be picked up by the slider 60 and displaced into the welding knife holder 40. Also visible in FIG. 4A is a temperature sensor 902 with which the temperature of the welding knife is detected and controlled.

FIG. 4B shows the partial view from FIG. 4A, with the welding knife 4 being inserted into the welding knife holder 40. Another welding knife 4 'is already pre-positioned for the next welding process. In the welding knife holder 40, the welding knife 4 is guided on crescent-shaped rails 55. For complete insertion of the welding blade 4, the slider 60 itself engages a little way into the welding knife holder 40. Before the further steps with vertical displacement of the welding knife holder 40 can be carried out from the "bladefeed position", the slider 60 therefore has to be moved out of the area of the welding knife holder 40 again by reversing its direction of movement. FIG. 4B already shows the slide 60 Back a little way back.

FIG. 4B shows the welding knife 4 in a preferred embodiment. Along its two shorter sides of the rectangle run edge portions 4 "and 4"'. When inserted, these edge regions 4 "and 4"'are contacted by the first and second clamping parts 43, 44 (not visible). For a good electrical contact, the clamping part 44 on the inside of the upstanding portions of the clamping arms 441 projecting contact points, preferably in the form of resilient plungers, on. In the vicinity of the edge regions, the welding knife has 4 recesses 48, which are designed as holes along the two short sides of the rectangle. Along its lower side of the rectangle, the welding knife 4 is punctiform on the crescent-shaped rails 55. 5 shows a sectional view of the device according to the invention, wherein the platform 400, with the aid of which the welding knife holder 40 is moved in the vertical direction of the arrow Y, is in the so-called "pre-cut position." Opposite and starting from the "bladefeed position" According to Figure 4, the platform 400 is moved a bit far up. In this position, the scanning wheel 52 above the second slide carrier 45 is now out of engagement with the second slide 451 in a so-called contacting position (A). In this position, the two clamping members 43, 44 are no longer held by the second link 451 at a distance from each other, but can now pinch the welding knife 4 between them, wherein it is contacted simultaneously electrically. In this position, the electrical heating of the welding blade 4 then takes place.

6 shows a sectional view of the device according to the invention, wherein the platform 400 with which the welding knife holder 40 is moved in the vertical direction of the arrow Y is in the so-called "stretch position." Compared with FIG is moved further in the direction of the table 700 and the scanning wheels 53 are now located at the first scenes 41 1 in a position in which the distance between the two hose holder 1 00, 200 assumes the highest value d4 The hoses of the first and second hose group 2. The first scenes 41 1 arranged on the link carriers 41 are designed so that this distance d4 in the subsequent further movement of the platform 400 in Direction of the table 700, during which the cutting blade 4 cuts through the tubes, is maintained. The hoses are thereby severed in the stretched state.

Figure 7 shows a sectional view of the inventive device, wherein the platform 400 is in the so-called "cut position", in which the hoses of the first and the second hose group 1, 2 are severed.

Immediately after the hoses have been cut, the cut ends 1 'of the hoses of the first hose group must be aligned with the cut ends 2' of the hoses of the second hose group in height. For this purpose, the second tube holder 200 is vertically displaceable and biased by a third spring 80 upwards. However, this movement of the second tube holder 200 is blocked in the positions described so far by the engagement of a stop surface 720 on a latch 72 which is horizontally displaceable in the table 700 and biased by a fourth spring 71 against the second tube holder. The unlocking of the second tube holder 200 by retracting the stop surface 720 is effected by engaging a cone 47 mounted on the platform 400 in an eccentrically arranged to this hollow cone 70 on the underside of the bolt 72. The fourth spring 71 is compressed. 6, the cone 47 already begins to slide into the hollow cone 70 in the "stretch position." The cone 47 and the hollow cone 70 are matched to one another such that the locking of the second tube holder 200 during the vertical movement the platform 400 is released as soon as the hoses of both hose groups 1, 2 are completely severed.After releasing the lock, the third spring 80 pushes the second hose holder 200 upwards.

As shown in FIG. 7, in the "cut position", the cone 47 engages completely in the hollow cone 70 and has released the lock of the second tube holder 200, as shown in FIG that this could be moved by the third spring 80 upwards. As a result, the cut ends 1 'of the hoses of the first hose group are aligned with the cut ends 2' of the hoses of the second hose group in height. The welding knife 4 is still between the hoses. The platform 400 has reached its highest position in the "cut position." The scanning wheel 52 of the second slide 451 is still above this in the contacting position (A), so that the welding knife 4 is clamped between the clamping parts 43, 44 The distance between the tube holders 1 00, 200 to each other at the distance d 2, which is dimensioned so that the cut ends 1 'and 2' on the first scenes 41 1 and the remaining ends 1 ", 2" are pressed against the hot welding knife 4 and thereby melted.

Thereafter, the welding knife 4 is moved out of the area of the cut hoses. This is done by the platform 400 and with her the welding blade holder 40 is now moved down. The reversal of their direction of movement takes place without reversing the direction of rotation of the motor 404 of the drive 401 automatically through the connecting rod 405. The scan wheels 53 pass through the first scenes 41 1 again the area they have already crossed over during the "stretch position" while of which the distance between the two tube holders 1 00, 200 has the larger value d 4 The tubes with their melted ends are thereby moved away a little by the welding knife 4, which facilitates its removal.Furthermore, no melting material, which is located at the melted ends by moving out transported away and is available for the subsequent welding. As the platform 400 continues to move downwards, the scanning wheels 53 on the first links 41 1 return to the area which they have traveled over during the "precut position" and during which the distance between the two tube holders 1 00, 200 has the smaller value d 3 As a result, one respective cut end V of the first hose group comes into contact with one cut end 2 'of the second hose group and is welded to continuous hoses Fig. 8, the platform 400 stops, so that the joined tubes and the remaining ends 1 ", 2", after cooling, can be removed from the device. 9 shows a sectional view of the device according to the invention, with the platform 400 and the welding knife holder 40 in the "eject position." In the "eject position", the platform 400 is in its lowest position. The welded hoses and the remaining ends have already been removed from the hose holders 100, 200. As already mentioned with reference to FIG. 4, the distance between the two clamping parts 43, 44 is set to one another by scanning the second slide 451 with the aid of a scanning wheel 52. If the welding knife holder 40 is in the "eject position", the scanning wheel 52 of the second link 451 is in a release position (C). The first clamping member 43 was moved against the action of the first springs 51 (not visible in FIG second clamping part 44 is moved so that the gap width between the two clamping parts 43, 44 is opened to the maximum distance.The welding knife 4 is then free and can fall out of the welding knife holder 40 into a disposal box (not shown in FIG.

9, the second tube holder 200 is returned from its upwardly displaced position to its initial position at the same height as the first tube holder 100. In the transition from the "Press Position" according to FIG. 8 to the "Eject Position" according to FIG. moved. At the same time, the third spring 80 is tensioned. A return mechanism 800 with a pull rod 81 coupled to the second hose holder 200 serves this purpose. When driving down, the platform 400 strikes against a stop 82 of the drawbar 81 and pulls it down with it. The cone 47 also comes out of engagement with the hollow cone 70, so that the stop surface 720 engage in the second tube holder 200 as before. The second hose holder is in its initial position at the same height with the first hose holder 1 00.

When driving down into the "eject position", finally, the scanning wheels 53 also come out of engagement with the first links 41 1 on the link supports 41. The distance between the two hose holders 100, 200 decreases so far that the hose holder 1 00 , 200 touch each other.

Figure 10 shows the preferred embodiment of the welding blade 4 in a rectangular shape with recesses 48, each arranged in a row along the edge regions 4 ", 4"'of the two shorter rectangular sides. The welding knife 4 is preferably made by half longitudinal folding of a double width sheet. As the blade 50, which cuts the tubes, the bending edge along which the two halves of the leaflet are connected serves. As an alternative to folding, the welding knife 4 is produced by stamping and its blade 50 by embossing. As a result of this design, a cutting edge which is not too sharp but rounded, but above all even and symmetrical on both sides, is provided in a rational manner. The latter is important so that the cutting blade is not deflected to one side when cutting the hoses, as would be the case for example with an asymmetrically ground edge. The blade 50, which cuts the tubes, runs along one of the two longer rectangular sides.

The welding knife 4 has for example a length between 60-80 mm, in particular of 70 mm, a width between 1 5-20 mm, in particular of 1 7 mm and a thickness between 0.2-0.5 mm, in particular of 0.3 mm. The size of the melt surface 49 depends primarily on the diameter of the tubes and on the number of hoses to be concealed.

The material used for the welding knife 4 is, for example, chromium / nickel steel. For a high-quality welding result is relevant, the horizontal and the vertical temperature distribution over the surface of the welding knife. It has been found that the arrangement of the recesses along the edge regions 4 ", 4" 'leads to a more homogeneous vertical heat distribution. The desired temperature of the welding knife is approx. 300 ° C. Figure 1 1 shows another embodiment of a welding blade 56. Here, per perimeter zone 58, 58 ', for example, each six, preferably circular recesses 57 are arranged. The number and the geometric shape of this recess is not limited to the number shown and a circular shape.

The ratio between web width to slot width or diameter is 60% in the embodiment shown. The illustration below shows the measurement protocol with the horizontal temperature distribution along three dashed lines 59 ', 59 ", 59'". The measurement protocols can also read the vertical temperature Distribution. The lines 59 ', 59 ", 59"' were selected at a height in which the hoses are later passed through in the device according to the invention.

The protocol is based on images taken with a thermal imager. In this protocol, the horizontal temperature distribution is shown along the lines 59 ', 59 ", 59"'. The profile "line 3" corresponds to the measurement along the line 59 ', the profile "line 1", that along the line 59 "and the profile" line 2 "that along the line 59"' indicated on the y-axis Values of the pixels correspond to horizontal length units along lines 59 ', 59 ", 59"'.

The welding knife 56 was clamped for measuring the temperature distribution in the welding knife holder 40 comprising the first and the second clamping part 43,44 and blackened for the measurement. The welding knife closes the secondary circuit of the transformer unit and is due to its high resistance value heated to a target temperature of about 300 ° C. It could be determined that the optimal temperature distribution (300 ° C +/- 5 ° C) was reached within 3-4 seconds. In the experiments it was further found that the contact of the welding knife by the two clamping parts has an influence on the vertical temperature distribution. A symmetrical distribution of the clamping force along the two edge zones has proven to be relevant for the vertical temperature distribution. One possibility for this are preferably resilient pressure pieces arranged on at least one of the two clamping parts. With the help of these plungers a symmetrical contacting is achieved by the compressive force of all plungers is set approximately equal.

NAME LIST

1 hoses of the first hose group 'Cut ends of the hoses of the first hose group

"Remaining ends of the hoses of the first hose group

Hoses of the second hose group

'Cut ends of the hoses of the second hose group

"Remaining ends of the tubes of the second tube group

00 First hose holder

01 first hose clamp of the first hose holder

02 second hose clamp of the first hose holder

1 first spring

1 through holes through first hose clamp second hose clamp 2 through holes through second hose clamp first hose holder00 second hose clamp

01 first hose clamp of the second hose holder

02 second hose clamp of the second hose holder

03, 203 'second springs

1 through holes through first hose clamp second hose clamp2 through holes through second hose clamp second hose clamp1 first pinch zone

2 second crush zone

sweat scraper

'another welding knife

", 4" 'border areas

0 welding knife holder

1 a pair of backdrops

2 slot

3 first clamping part

4 second clamping part 45 second slide carrier

47 cones

48 recesses

49 Melting surface

50 blade

51 first springs

52 scanning wheel of the second backdrop

53 Abtastradpaar the first backdrop

55 half moon shaped rails

56 welding knives

57 circular recesses

58, 58 'edge zone

59 ', 59 ", 59'" three dashed lines

400 Platform for positioning the welding knife holder 401 Drive for the platform

402, 403, 407 gears

404 engine

405 connecting rods

406 rod-shaped guide

41 1 four first scenes

431, 441 angled clamping arms

451 second backdrop

500 box with welding knives

520 rod-shaped guide

600 welding knife feeder

60 slides

61 guide rails 601 sleds

602 Drive for welding knife feeder

603 timing belt

700 table

70 hollow cone

71 fourth springs

72 bars

720 stop surface

701 four legs

702 detail

704 drawer

705 start button

1 0, 20 tension levers

800 return mechanism

80 third spring

81 drawbar

82 stop

90 transformer unit

901 screw

902 temperature sensor

Contacting position (A)

Recording position (B)

Release position (C)

Claims

claims

1. A device for welding thermoplastic tubes of a first and second tube group (1, 2), comprising two tube holders (100, 200) each having a first (101, 201) and a second tube clamp (102, 202) and a welding knife (4 ), wherein the tubes of the first tube group (1) straight in between the two tube holders (100, 200) in through holes (11, 21) of the two first tube clamps (101, 201) can be inserted and squeezed therein, the tubes of the second Hose group (2) straight in between the two hose holders (100, 200) in through holes (12, 22) of the two second hose clamps (102, 202) can be inserted and squeezed therein, wherein the welding knife (4) between the first and the second Hose holder (100, 200) can be moved and is adapted to thereby durchtre the crimped tubes of the first and the second tube group (1, 2) in one movement In order to produce in this way cut ends (1 ', 2') and residual ends (1 ", 2"), wherein one of the two tube holders (100, 200) relative to the other tube holder (100, 200) are moved can, to thereby align the cut ends (1 ', 2') of the hoses, and wherein the two tube holders (100, 200) can be displaced in a horizontal direction towards each other or away from each other, thereby each having a cut end (V) of a tube of the first tube group (1) each having a cut end (2 ' ) of a hose of the second hose group (2) to a continuous hose at the same time to weld.

Apparatus according to claim 1, characterized in that the passage openings (11, 21) of the two first hose clamps (101, 201) on a first level and the passage openings (12, 22) of the two second hose clamps (102, 202) on a second level are arranged, wherein the first plane is arranged parallel and spaced from the second plane.

Apparatus according to claim 1 or 2, characterized in that the two first hose clamps (101, 201) and the two second hose clamps (102, 202) have pinch zones (31, 32), wherein these pinch zones (31, 32) along the through holes (31 11, 21, 12, 22) and are adapted to squeeze the inserted tubes at an oblique angle to the first and to the second plane.

Device according to one of the preceding claims, characterized in that the welding knife (4) can be clamped in a welding knife holder (40) and a drive unit (401) is arranged to move the welding knife holder (40) in a vertical direction for severing the tubes and thereby one of the two tube holders (100, 200) relative to the other tube holder (100, 200) for aligning the cut ends (1 ', 2') of the tubes is vertically displaceable.

5. The device according to claim 4, characterized in that by the movement of the welding knife holder (40) in the vertical direction further, the two hose holder (1 00, 200) in the horizontal direction, on each other or away from each other or both hose holder (1 00 , 200) are movable simultaneously in one direction.

6. The device according to claim 5, characterized in that the device has a movable in the vertical direction platform (400) and the welding knife holder (40) on this platform (400) is arranged.

7. Device according to one of claims 4 to 6, characterized in that the welding knife holder (40) has two opposing clamping parts (43, 44), between which the welding knife (4) can be clamped, preferably one of the two clamping parts fixed and the other is arranged relatively movable to the fixed clamping part.

8. The device according to claim 7, characterized in that at least one of the two clamping parts (43, 44) is provided a pair of first link supports (41) and the pair of link supports (41), preferably a total of four first scenes (41 1) having, these scenes (41 1) are arranged identical to each other and mirror-symmetrical to a plane of the welding blade (4) when the welding blade (4) is clamped between the two clamping parts.

9. Apparatus according to claim 8, characterized in that Abtastaster pairs (53) are provided, in the movement of the welding blade holder (40) in the vertical direction, the scenes (41 1) scan and thereby the two hose holder (100, 200) in the horizontal direction to each other, or away from each other, or both hose holder (100, 200) are simultaneously movable in one direction.

10. Device according to one of claims 7 to 9, characterized in that a second slide carrier (45) and a further Abtastrad (52) are provided, wherein the further Abtastrad (52) is adapted to, during the movement of the welding knife holder (40). in the vertical direction to scan the second link carrier (45) to thereby move the one clamping part (43) relative to the second fixed clamping part (44) and in this way the distance between the two clamping parts (43, 44) is variable.

1 1. Apparatus according to claim 1 0, characterized in that the scanning of the second link carrier (45) by the further Abtastrad (52), wherein three different positions are possible, namely a first contacting position (A) in which the distance between the two clamping parts is selected so that the welding blade (4) is clamped and simultaneously contacted electrically, a second position (C) in which the distance between the two clamping parts (43, 44) selected so that the welding knife can be ejected and a receiving position (B) in which the distance between the two clamping parts (43, 44) is selected so that the welding knife between the two clamping parts (43, 44) can be inserted.

12. The device according to claim 1 1, characterized in that at least one of the two clamping parts (43, 44) pressure pieces are arranged, which contact the welding blade (4) in the contacting position (A), said pressure pieces on the at least one clamping part ( 43, 44) are resiliently mounted.

13. Device according to one of claims 7 to 1 2, characterized in that the device further comprises a transformer unit (90) having a primary winding and a secondary winding, wherein the secondary winding is formed by a single conductor and this conductor with one of the two clamping parts ( 43, 44), preferably with the fixed clamping part (44) is connected, wherein the welding knife (4) in the contacting position (A) closes the secondary circuit and is heated in this way to the desired temperature.

14. Device according to one of the preceding claims, characterized in that the first and the second hose group (1, 2) each have the same number of individual hoses, preferably more than two, in particular six hoses, per hose group (1, 2).

15. A method for welding a plurality of tubes of a first and a second tube group (1, 2) with a device according to one of the preceding claims 1 to 1 4, wherein in one step, the tubes of the first and second tube group in parallel and one above the other in itself opposite first (1 00) and second hose holder (200) straight inserted and squeezed and inserted a heated welding knife (4) in a welding knife holder (4) and heated to a desired temperature, the heated welding knife (4) between the the first and second tube holders (100, 200) are moved while simultaneously severing the crimped tubes into cut ends (1 ', 2') and remainder ends (1 ", 2"), the cut ends (V , 2 ') of the hoses are melted by the heated welding knife (4), the cut ends (1 ') of the tubes of the first tube group (1) are aligned with the cut ends (2') of the tubes of the second tube group (2), one of the two tube holders (100, 200) relative to the other Hose holder (1 00, 200) is moved so that the cut ends (V) of the hoses of the first hose group (1) symmetrically opposite to the cut ends (2 ') of the second hose group (2) are arranged, the two hose holder (1 00, 200) are shifted towards each other by a respective cutting end (1 ') of the tubes of the first tube group (1), each having a cut end (2') of the tubes of the second tube group (2) to one each continuous tube to be welded simultaneously, the welding knife (4) from the welding knife holder (40) is ejected.

16. The method according to claim 1 5, characterized in that when inserting the welding blade (4), the horizontal distance between the first and the second hose holder (1 00, 200) d 1, i s in the severing of the crimped hoses the distance d4 on vergrösserst is, when melting the cut ends of the distance is d2, where d 1 <d2 <d4, when moving one of the two hose holder (1 00, 200), the distance is increased back to d4, when welding the distance d3, where d3 <d4 and when the welding knife of the cut ends (V, 2 ') is ejected, the distance between the two hose holders (100, 200) is d5, where d5 is the smallest of all five distances (d 1, d2, d3, d4 ).

17. Welding knife, characterized in that the welding knife (4) in its melt surface (49) has a plurality of recesses (48).

18. Welding knife according to claim 1 7, characterized in that the melt surface (49) has a rectangular shape and along the two shorter sides of the rectangle (4 \ 4 ") edge zones are provided, which are adapted to a secondary side (92) of a Contact transformer unit (90).

19. Welding knife according to claim 1 8, characterized in that the recesses (48) along the edge zones of the melt surface (49) are arranged.

20. Welding knife according to one of claims 1 7 to 1 9, characterized in that the welding knife (4) on one of the two longer sides of the rectangle has a blade (50), wherein the blade (50) based on the cross section of the rectangle, has a symmetrical shape.

21. Welding knife according to one of claims 1 7 to 20, characterized in that the blade (50) is formed by a bending edge resulting from a half longitudinal folding of a leaflet or the blade (50) is embossed along a longitudinal side of the leaflet.

22 box comprising a plurality of welding knives according to claims 1 7 to 21, wherein the box is preferably interchangeable as a whole.